fix Issue 12024 - template instantiation for swap(SysTime, SysTime) fails
Fix union case
Move isBlitAssignable to std.traits
Fix for enum and alias this cases
Fixed typo.
Merge pull request #1891 from 9rnsr/fix12024

[REG2.065a] Issue 12024 - template instantiation for swap(SysTime, SysTime) fails